1. Field of the Invention
The present invention relates to an ink (UV-curable decolorizable ink) containing a coloring component which is decolorizable by the ultraviolet light and a curing component which is curable by the ultraviolet light, a printing apparatus for performing a printing process and a decolorizing process by using the UV-curable decolorizable ink, and a program, a storage medium, and a method to be used therefor.
2. Description of the Related Art
In recent years, as the progress of office automation is advanced, the opportunities are increased, in which the computer data is printed on the paper, for example, for the purpose of the hard copy. In such situations, the amount of consumption of the paper is increased. Therefore, the deforestation is carried out in succession in order to secure the wood to be used as the raw material of the paper, and the serious environmental problem, i.e., the forest destruction is caused. In view of the above, a countermeasure is suggested such that the image, which has been printed on the paper, is erased, and the paper, which has been subjected to the printing, is reused without being discarded.
For example, an ink-jet printer, which is disclosed in Japanese Patent Application Laid-open No. 5-185588, uses a water base ink containing a dye which is modified and decolorized when the ultraviolet light is radiated thereon. The ink-jet printer is provided with an ultraviolet radiation lamp at the upstream of an ink-jet head for jetting the ink. According to this ink-jet printer, when the ordinary printing is performed, then the paper sheet is transported in a state in which the ultraviolet radiation lamp is turned OFF, and the ink-jet head is driven so that the ink is discharged toward the paper sheet to perform the printing. On the other hand, when the printed image is erased, then the paper sheet is transported in a state in which the driving of the ink-jet head is stopped, and the ultraviolet radiation lamp is turned ON. The dye of the ink is decolorized by the ultraviolet light radiated from the ultraviolet radiation lamp, and the paper sheet is discharged while returning into the blank paper state.
However, the ink-jet printer disclosed in Japanese Patent Application Laid-open No. 5-185588 uses the water base ink. Therefore, when the ink is discharged from the ink-jet head, and the ink is deposited to the paper sheet, then water or the like as the solvent is evaporated, and the dye, which is decolorizable by the ultraviolet light, is deeply permeated into the fiber of the paper. In such a situation, the ultraviolet light, which is radiated from the ultraviolet radiation lamp, is hardly absorbed by the dye sufficiently, and it takes a long period of time in order to completely erase the printed image. Further, when the water base ink is used, a problem also arises such that the printing is hardly performed on any medium which has the low water permeability.